US2505612A - Bar feed for lathes and the like - Google Patents

Description

April 25, 1950 A. A. ERlcsoN BAR FEED FOR LATHES AND THE LIKE Filed Dec. 20, 1944 lNvEToR ATTORNEYS /MBE/Q A. 7e/c 50N.

BY m, @ma f Nw.. QA

Patented Apr. 25, `1950 BAR FEED FOR LATI-IES AND THE LIKE Albert A. Ericson, Massapequa Park, N. Y., assignor to The Farmingdale Corporation, a corporation of New York Application December 20, 1944, Serial No. 568,961

1 Claim.

This invention relates to devices for feeding bar stock used in machine tools, and is particularly applicable to the feeding of the bar stock commonly used in turret lathes, screw machines, and similar tools in which the bar stock is fed through a hollow head stock spindle to a chuck or collet which grips the forward end of the stock where it is operated on by one or more tools. After the necessary operations have been performed the formed end of the bar is cut olf, the chuck is released, and the bar fed forward so as to present another work piece. As machines of this type are utilized for the production of large numbers of parts, it is desirable to provide means for rapidly feeding the stock and opening and closing the chuck or collet to grip the stock in working position. In machines of this kind the bar of stock rotates at high speed with the spindle of the lathe while the work is being performed and it is necessary that the feed device be of such nature that it will not interfere with this rapid rotation of the 'stock during the turning operations. It is necessary that the feed device be of such nature that the surface of the stock will not be marred during feeding or during rotation of the stock.

In many prior feed devices it has been customary to clamp a collar on the stock by means of a set screw or the like, and to feed by pushing against this collar. Such devices are objectionable as such screw is likely to damage the surface of the stock and furthermore at frequent intervals it is necessary for the operator to stop and loosen the collar and move it along to a new position upon the bar of stock. This delays the operation of the machine.

Among the objects of the present invention are the provision of a bar feed device which will firmly grip and advance the bar without marring the surface; which will permit the bar to rotate freely without injury to its surface during periods when work is being performed on the Work piece; which will grip and advance the bar step by step throughout its length without requiring manual adjustments of a collar or the like; and which can be linked up with the means for operating the chuck or collet so that a single hand lever may be utilized to release the chuck, feed the stock, and reclose the chuck.

In the accompanying drawings I have shown one preferred embodiment of the invention as illustrative of the principles thereof but it is to be understood that changes may be made therein without departing from the invention.

In the drawings:

Figure l is a side elevation of a part of a turret lathe having the bar feed device of my invention applied thereto, part of the head stock of the lathe being shown in longitudinal vertical section;

Figure 2 is a transverse vertical section taken on the line 2 2 of Figure l;`

Figure 3 is a longitudinal vertical section of 2 the parts shown in Figure 2, taken on the line 3-3 of Figure 2; and

Figure 4 is a perspective view of the movable bar gripping member.

Referring to the drawings in detail, i0 is a turret lathe having a bed i2 upon which is mounted a head stock ill and a turret i6. The head stock carries a spindle I8 mounted in bearings in the head stock and arranged to be driven in any suitable manner as by means of the cone pulley 2D. The spindle I8 is provided with any suitable form of gripping chuck or collet, Such for instance as the series of spring collet members 22 having tapered outer faces 24 which engage the internal cone 26 at the end of the head stock spindle and are thereby caused to clamp the bar of stock 28. The members 22 are connected to a sleeve 3Q which when moved to the left (Fig. 1) causes the members 22 to clamp the bar, and when moved to the right releases the bar. For operating the clutch the sleeve 30 is shown as provided with a collar 32 which is engaged by a grooved collar 34 mounted on a slidable sleeve 3B. The grooved collar 34 is engaged by fork 38 carried on sleeve 40 mounted to reciprocate on a guide rod 42. The sleeve 4B is moved on the guide rod by link 5i) connected to an arm 52 mounted on a shaft 54 which may be oscillated by means of a hand lever 56. Movement of the hand lever to the left as seen in Figure 1 will cause the chuck to clamp the bar and movement of the lever to the right will release the chuck so as to permit the bar to be advanced. This arrangement is conventional and any suitable equivalent chuck arrangement may be employed.

The bar feed device comprises a feeding clamp $0 adapted to intermittently grip the bar when it is to be fed and to release the bar so as to permit it to rotate freely therein at times while the bar is being rotated and Work performed upon it by one or more of the tools carried by the turret i6. In the construction shown, the clamp comprises Va bearing sleeve 52 having a smooth inner surface and having a sector cut out preferably at the bottom as indicated at 64 for instance (Fig. 2). The bearing sleeve 62 is mounted in a recess in a pillow block 6B and is held therein by a cap 68 clamped down by screws lil. A screw 'i2 may be screwed through the cap into the bearing sleeve to prevent it from rotation. The bearing sleeve is preferably provided with flanges M tting on each side of the pillow block and cap. The pillow block is preferably provided with a slot 'it formed therethrough below the cut out sector of the bearing sleeve. A clamping block el] of the form shown in Fig. 4 is provided to fit loosely in the cut out sector E4, this block having a concave surface 82 conforming to the curvature of the bore of the bearing sleeve 62 and being shown as provided with end flange portions 8d. The bearing sleeve t2 and clamping block #B0 may conveniently be made by machining a cylindrical sleeve and. then sawing out a piece to constitute the vclamping block 80. The bearing sleeve and block may be formed of any suitable material of the necessary durability and preferably of some metal forming a good bearingI material, suchias bearing bronze. A smooth. andA durable inner surface of these parts is desirable because the formed stock rotates therein at high speed during the machining operations. The clamping block 88 is preferably sufficiently wider than the slot 18 in the pillow block so that the ends of the flanges 3ft will overhang the corners of the pillow block at each side of the slot and thereby retain the bearing block 89 in the cut out sector 84. The fit however is-suiiiciently looserto permit the clamping block to have a slight radial movement. The clamping block rests. upon a concavely grooved eccentric cam 90 mounted in the slot 'i8 and keyed upon a shaft 92 journalled in the pillow block.

The shaft 92 may be given a limited movement of rotation by cranks 94 mounted on the ends thereof', the cranks being suitably keyed or pinned tothe ends of the shaft 92. Rotation of the shaft 8". by the cranks willv turn eccentric 90 so as to move the clamping block 8: into clamping engagement with the bar 32 when the shaft 92 is rotated in a counterclockwise direction, as seen inlig.l 3; Turning of the shaft and eccentric in the opposite direction will obviously release the clamping pressure upon the bar stock. For turning the cranks and eccentric the cranks are conneotedby meansof links 99 to a pair of levers 98 pivcted at their lower ends toA a bracket 198 on the bed ofthe lathe. The levers 98 have slots E82 between their ends, these slots receiving pins [Se mounted on the sleeve 59V which is reciprocated on the guideV rod 42 by movement of the hand lever 56 as already described'. This lever arrangement multipl-ies the movement ofy the feed clamp S with respect tothe movement of the sleeve 40.

The pillow block 5S has a bearing opening H9 formed in its lower end and is slidably mounted upon the guide bar 42. In order to supplement the bearing of the pillow block on the guide bar, a. bearing block H2 is preferably bolted to the pillow block byscrews l-I 4. preferably provided with a keyway H8 in which slidesY a key or feather H8 carried in the pillo-w block and bearing block H2. This keyway and feather act to hold the pillow block and bearing sleeve 92 in proper alignment with the lathe spindle. Y

In operation it is to be seen that the operator merely has to manipulate-the hand lever 58. Assuming'that the bar stock is'clamped in the chuck and a piece has been finished by the operations of the tools in the turret, the operator moves the Vhand lever 56 to the right (Fig. 1)'. This releases the clamping engagement of the members 22 upon the bar 32. Movement of the hand lever to theright will also pull on the links 98 thus rotating the shaft 92 in a counterclockwise direction, which will similarly rotate the eccentric 99 and thus cause the clamping block 82 to clamp'the bar 25 within the bearing sleeve 92. Further movement of the hand lever to the right willaccordingly advance the bar 28 to the right. Movement of the hand lever to the left will first release the grip of the feed cla-mp 60 on the bar, will then move the feed clamp to the left where it isy in a position to take a new grip on the bar, and finally will cause the chuck to grip the bar. The feeding movement of the bar stock by means The guide bar 42 is of the feed clamp 60 is produced by the manipulationlof the lever prior` to the closing of the chuck. It will be seen that if necessary the hand lever 56 may be moved back and forth two or three times before it is moved far enough to the left to close the chuck and each of these movements will operate the eccentric 9i) so as to grip the bar which is thereby advanced in two or three short steps. In this way any desired feed of the bar may besecured prior to locking the saine in the chuck. In fact by repeated movements of the hand lever 56 long lengths of stock may be fed if such are required for the purposes inhand.

It will be seen-that the interior of the sleeve 62 and clamping blocky surface 82- aresmooth and form av practically cylindrical bearing for engagement with thev rotatingv bar stock, so thatV they will act asa guide for the stock permitting free rotation thereof and holding the` stock in proper'alignment. Furthermore-'the surfaces besmooth will not mar the surface of theV stock either during feeding or rotation thereof.

The block ilmay-l evidently be readily replaced in case of wear, asalso mayY the sleeve 62. The sleeve 92 and block may also be replaced with similar members of different internal diameter suited to the particular diameter of stock beingv used.

While I have illustrated Vand described in detail certain preferred forms of my invention, it is toA be understood that changes may be made therein and the invention embodied in other structures.

I do not, therefore, desire to limit myself` to the specific constructionillustrated, but intend to cover my invention broadly in whatever form its principles may be utilized.

What is claimed is:

A bar feed device for lathes and the like having a driven spindle carrying a work clamping chuck, a longitudinal guide, a bar feed member mounted for reciprocable movement thereon, a bar clamp carried by said bar feed member, an opera-ling arm for said clamp and means for reciprocating said bar feed member and actuating said clamp operating arm comprising a link connected to said-operating arm, and -a lever for reciprocating said link, said lever being fulcrumed to a fixedy support at its end opposite to that at which said link is connected, said lever having a slot between its ends, a chuck operatingV member mounted to reciprocate on said longitudinal guide having a pin working in the slot in the lever, operative connections between said chuck operating member and chuck, a hand lever, and connections between said hand lever and saidchuck operating member for reciprocating said member on said guide.

. ALBERT A. ERICSON.

REFERENCES CITED The following references are of record, in the file of this patent:

UNITEDY STATES PATENTS Number Name Date 434,204 Rothlisberger Aug. l2, 1890 624,491 Hoffmann May 9, 1899 r114,895 Hanson Dec. 2, 1902 1,526,050 Carmichael Feb.Y 10, 1925r 2,368,890 Sherrow Feb. 6, 1945 2,388,594 Bogart Nov. 8, 1945 FOREIGN PATENTS Number Country Date 510,312 Great Britain July 3,1, 1939

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